An automatic analyzer is practiced as an apparatus for analyzing sera, urine, etc. of patients. Such an analyzer comprises a sample table including a sample vessel which contains a sample, such as a serum, a sampling mechanism for dispensing the sample, a reaction table including a reaction vessel in which the sample is mixed with a reagent to prepare a reaction solution and to develop a reaction, an agitating mechanism for agitating and mixing the reaction solution, a photometer for measuring the absorbance of the reaction solution, and a cleaning mechanism for cleaning the reaction vessel.
Further, the analyzer comprises two reagent tables on which a first reagent and a second reagent are loaded respectively as reagents to be added to the sample. Each of the reagent tables includes a driving mechanism for rotating the reagent table independently, and a reagent dispensing mechanism for sucking the reagent.
Recently, there has been an increasing demand for an analyzer capable of performing both biochemical analysis and immunity analysis by a single unit, which have been performed so far by separate dedicated analyzers. It is hence required to accurately perform a wide range of analysis covering from biochemical analysis to immunity analysis.
Accordingly, a demand for increasing the number of analysis items loadable on the automatic analyzer, i.e., the number of reagents, has also increased.
In view of such a demand, JP,A 9-72915 proposes a reagent storage in the form of a turntable for loading reagents thereon, in which reagent vessels are arranged along a plurality of circles in a concentric relation corresponding to the increasing number of reagents, and barcodes of the reagent thus arranged can be read.
In general, reagent vessels are employed such that sector-shaped reagent vessels are arranged on a reagent table in an annular form, or that rectangular reagent vessels are arranged in a matrix pattern. As a reagent dispensing mechanism, a rotating mechanism and an XY-mechanism are employed for the sector-shaped and rectangular reagent vessels, respectively, to perform dispensation of reagents and analysis of samples with high efficiency.
However, the number of reagents loadable on the reagent table is determined depending on the size of the reagent table itself. Therefore, if two reagent tables are arranged independently of each other and reagents are sucked and ejected from the reagent tables by using respective reagent dispensing mechanisms, the size of the reagent table is enlarged as the number of loadable reagents increases. As a result, the size of a body of the automatic analyzer is enlarged and so is the reagent dispensing mechanism.
Also, in the analyzer employing the rectangular reagent vessels arranged in a matrix pattern, the travel distance of the XY-mechanism becomes longer with an increase in the number of loadable reagents, and therefore the analyzer is not adaptable as a machine of high processing capability with a shorter cycle time.
Thus, even in the field of a multi-item analyzer requiring a large number of loadable reagents, it has been demanded to develop a small-sized analyzer having a high processing capability and high reliability.
To that end, JP,A 4-36658 discloses an automatic analyzer comprising a reagent storage in which a plurality of reagent vessels can be arranged in an annular form, reagent vessel carrying-in means for carrying the reagent vessel into the reagent storage in the radial direction of the reagent storage, and reagent vessel carrying-out means for carrying the reagent vessel out of the reagent storage in the radial direction of the reagent storage, wherein the reagent vessel can be carried out and in even during analysis of a sample.
With that construction, the number of loadable reagents can be increased without essentially enlarging the size of the reagent storage.
Additionally, other similar techniques regarding the automatic analyzer are disclosed in, e.g., JP,A 4-43962 and JP,A 4-50654.